While I realize these have been around for awhile, I thought I would post some links to great webcasts discussing different aspects of Commerce Server 2007.

Commerce Server 2007 Architectural Deep-Dive by David Messner
Commerce Server 2007 Data Warehouse by Brian Blum and Alan Faulkner
Commerce Server 2007 BizTalk Adapters in Action by Brian Blum and Alan Faulkner
Developing with the Commerce Server 2007 Marketing System by Madhur Joshi and David Lott
Commerce Server 2007 Product Catalog Deep-dive by Austin Skyles
Commerce Server 2007 Overview by Mark Townsend
Multi-Channel, Connected Commerce (BTS/CS integration) by Caesar Samsi

These are all great webcasts, and I encourage anyone looking to learn more about CS 2007 to watch them.

Here are some other invaluable links:

MSDN - Commerce Server 2007
MSDN - Common Development Tasks with Commerce Server 2007
Commerce Server 2007 Forum
Core Systems Overview - Jeff Lynch

Best of luck!